A method of this type for carrying out working steps on miniaturised modules in at least one work station is known from the German patent 196 37 822, wherein the modules are held by a module carrier which is provided with a holding device.
However, a method of this type merely envisaged a single work station so that further processing of a module was not possible.
Consequently, the object of the invention is to provide a method which enables a plurality of working steps to be carried out on a module.
In accordance with the invention, this object is achieved in the case of a method of the type described hereinabove in that, for the purposes of carrying out the working steps, the module is moved by the same module carrier to a plurality of work stations and is precisely positioned for carrying out one of the working steps by means of a relative movement between the module carrier and the currently relevant one of the plurality of work stations, and in that the positioning of the module relative to the module carrier is maintained for carrying out the working steps.
The advantage of the solution in accordance with the invention can be seen primarily in that the number of possible working steps is multiplied by the number of work stations provided, and in that it is nevertheless possible to carry out the respective working steps with greater precision, despite having a plurality of work stations, by virtue of the precise positioning of the module carrier relative to the respective work station, and in that this precision is further improved for the relevant working step by virtue of the fact that the positioning of the module relative to the module carrier is maintained and hence any imprecision that could be caused thereby is excluded.
In principle, the positioning of the module relative to the module carrier could also be maintained if the module carrier were to deposit the module in the relevant work station for the associated processing thereof, although in this case it would be necessary to fix the module in the work station in a precise manner in order to enable the module carrier to subsequently pick up the module with the same level of precision. On the other hand, apart from the fact that such precise fixing in the respective work station signifies a considerable degree of effort, the subsequent picking up of the module by the module carrier will nevertheless be associated with a loss of precision.
For this reason, a particularly advantageous solution envisages that the module should continue to be held by the holding device in the module carrier whilst carrying out a sequence of working steps. By virtue of this solution, there will thus be no loss of precision whatsoever since the module will continue to be held by the holding device just as before, and hence the individual working steps in the individual work stations involve no loss of precision whatsoever in terms of orienting the module relative to the module carrier.
Such a process of carrying out the working steps in the case where the module is held by the module carrier can be carried out in an especially expedient manner if the sequence of working steps is effected in a mechanically non-contact making manner so that no great demands will be made in regard to the fixing of the module relative to the module carrier and hence this will be effected without the application of large forces which could, in turn, lead to a displacement of the module relative to the module carrier and consequently negatively affect the degree of precision.
It would be possible to use various means for effecting such a mechanically non-contact making process. For example, it would be conceivable to carry out such a mechanically non-contact making process by means of elementary particles, neutral particles or ions.
However, the working steps can be carried out in a particularly simple manner if they are carried out by means of electromagnetic radiation since such radiation can easily be produced and employed for the individual working steps and, for example, it can be focused.
Within the framework of a working step in accordance with the invention, one could conceive of the most varied of functions, whereby every function which, for example, could be used for producing a miniaturised module, would fall thereunder.
For example, one could envisage that a process of fine positioning the module be carried out as one of the working steps so that the subsequent processing thereof will be carried out with the greatest possible degree of precision.
It has proved to be particularly advantageous hereby, if an exact position of the module relative to the module carrier is determined during the fine positioning working step and if this is then made available for the subsequent working steps. For example, it is thereby possible, when subsequently positioning the module carrier relative to the then relevant work station, to inevitably achieve the same level of precision in regard to the position of the module relative to the work station due to the precisely known position of the module relative to the module carrier.
Such a process of determining the position of the module relative to the module carrier could be carried out in a manner similar to a calibration process for example, that is to say, the deviation of the position of the module from an ideal position relative to the module carrier is determined, whence the positioning required for the subsequent working steps can be corrected.
This process creates the possibility of tolerating a certain error of positioning when gripping or picking up the module by means of the holding device, whereafter however, a determination is made by the fine positioning process and this is then taken into account in all of the following processing steps so that the actual process of picking up the module by the holding device can be simplified and a not too high level of precision has to be maintained thereby.
In regard to the positioning of the module relative to the currently relevant work station, it has proved to be particularly expedient if a controlled relative positioning between the module carrier and the work station is carried out in each work station, this being effected by positioning elements disposed thereat so that a very high degree of precision can always be maintained in the course of a working step which has to be carried out subsequently.
In regard to the type of working steps provided in a work station, no detailed comments in respect thereof have as yet been made. Thus, one advantageous embodiment envisages that exclusively non-contact making working steps should be carried out in one of the work stations so that the module can continue to be held by the holding device throughout the sequence of working steps carried out in this work station for example.
It is particularly advantageous however, if exclusively non-contact making working steps are carried out in a plurality of the work stations.
Non-contact making working steps of this type may also be of the most varied kinds, for example, it would be conceivable to provide a vaporising process using conventional heating of the material that is to be vaporised as the working step. However, it is advantageous in this case too, if the non-contact making working step is carried out by means of electromagnetic radiation. However, the working steps are capable of being carried out particularly homogeneously if they are carried out using electromagnetic radiation having a spatially uniform energy density distribution since similar physical interactions then take place in the whole processing region, and a reducing projection of complex structures on a mask located in the path of the beam is also possible.
It is particularly advantageous if the non-contact making working step is carried out by means of laser radiation.
A particularly uniform, extensive removal or deposition process can then be carried out in the working steps if the beam profile is rectangular or square since square or rectangular beam profiles can be composed very easily and can be precisely adapted to large surface areas.
The working steps can be carried out in a particularly precise manner however, if they are carried out using pulsed electromagnetic radiation wherein the pulses are so short that a transfer of energy from the electron system into the phonon system of the solid body being processed cannot be transferred during the duration of the pulses.
A particularly high level of precision can then be achieved if the working step is carried out by means of pulsed laser radiation, and preferably laser radiation in the pico-second range or in the femto-second range since a high level of precision can be achieved in any form of processing operation using such types of pulses due to the fact that thermal conduction effects, which have a negative effect on the precision of the processing operation when using laser radiation, can be avoided to a large extent when using laser pulses in the pico-second range.
For example, it would be conceivable for a process of applying a layer to the module to be carried out by means of laser radiation.
However, as an alternative, it would also be conceivable for a process of removing material from the module to be carried out by means of laser radiation.
Another possible form of working step would be the production of a jointed connection on the module by means of a process of supplying energy by electromagnetic radiation, preferably likewise by means of laser radiation.
In regard to the movement of the module carrier to the individual work stations, no detailed comments in respect thereof have as yet been made. Thus, one advantageous embodiment envisages that a module carrier be moved from one work station to another in correspondence with a defined sequence.
However, this method can be developed in a particularly efficient manner if it is not just one module carrier that is moved from one work station to another in correspondence with a defined sequence, but rather, if it is a plurality of module carriers, in the ideal case, a number of module carriers corresponding approximately to the number of work stations, that are moved from one work station to another in correspondence with a defined sequence so that a plurality of module carriers co-operate simultaneously with respective ones of the plurality of work stations.
The defined sequence may thereby either be fixed, or preferably, be freely programmable.
For implementing the movement of the module carriers from work station to work station, provision is preferably made for the module carriers to be movable relative to a base unit, whereby the position of the work stations is preferably fixed relative to the base unit. However, it is also possible to arrange the work stations such that, in addition to the module carriers, they too are movable relative to the base unit.
It is preferable hereby for the module carriers to be movable along arbitrary predefined paths on the base unit so that the method in accordance with the invention demonstrates the greatest degree of flexibility.
The module carriers can then be moved in a particularly expedient manner if they are supplied with control information in non-contact making manner and, for example, if they also transfer test data in non-contact making manner to the central unit.
This control information primarily concerns information in regard to the working steps that are to be carried out.
However, it is also conceivable that information in regard to the paths that are to be followed on the base unit be transmitted in non-contact making manner.
One particularly expedient solution envisages that the positioning of the module carriers should be controlled in non-contact making manner, that is to say, that the detection of the position of the module carrier along its path on the base unit should be effected in non-contact making manner so that the path of the module carrier between two work stations would also be controllable in non-contact making manner.
As an example, another particularly expedient solution envisages that test data in regard to the determination of the position of the module carrier be transmitted to the central unit in non-contact making manner.
In order to supply the module carrier with energy during its movement relative to the base unit, it would be conceivable to supply the energy over a flexible lead for example. However, it is particularly expedient if the module carriers are supplied with energy in non-contact making manner, for example, the transmission of energy could be provided hereby by means of induction, whereby the required energy could be transmitted directly, or, energy could be transmitted which is intermediately stored in the module carrier in an energy store, for example, an accumulator.
Moreover, the invention relates to a device for carrying out working steps on miniaturised modules, said device comprising a module carrier provided with a holding device for holding the modules and a work station for carrying out at least one working step, whereby the object of the invention is achieved in that there are provided a plurality of work stations, in that the module carrier is movable in such a manner that the module is precisely positionable by virtue of a relative movement between the module carrier and the work station for the purposes of carrying out the working steps in the plurality of work stations, and in that the module is adapted to be fixed by the holding device in a single relative position with respect to the module carrier for carrying out the working steps.
By virtue of this solution, it becomes possible to carry out a plurality of operational steps in an efficient manner on the one hand, and with high precision on the other, even in the case of miniaturised modules.
Provision is preferably made thereby for the module to be adapted to be fixed on a gripper head of the module carrier.
Hereby, the gripper could be constructed in the most varied of manners. For example, it would be possible to construct the gripper in the form of an electrostatic gripper which mechanically grips the module by means of an electrostatic drive system. However, a particularly simple type of construction envisages that the gripper head should comprise a vacuum gripper for the module, by means of which said vacuum gripper the module is drawn against a locating surface and is retained in position thereon by the application of a vacuum.
In order to be able to effect an at least adequately precise prepositioning of the module relative to the vacuum gripper during the process of picking up the module, provision is preferably made for a positioning device for the module to be integrated in the vacuum gripper whereby it is possible to grip the module in a positionally precise manner.
Hereby for example, the positioning device could be constructed such that it detects the shape of the module and aligns the vacuum gripper accordingly so that it can then act quickly on the module whereby this rapid gripping action can be effected xe2x80x9cblindlyxe2x80x9d once the vacuum gripper has been aligned. However, it is still more advantageous if the positioning device is formed such that it can detect a marking on the module, which marking is associated with a vacuum chamber of the vacuum gripper, since, in this case, the position of the marking can be detected even as the vacuum gripper is rapidly approaching the module whereby the vacuum gripper can still be controlled even during its rapid approach so as to grip the module in as exact a manner as possible.
Furthermore, in order to then be able to precisely position a module relative to the respective work station after the module has been gripped, provision is preferably made for the gripper head and each of the work stations to comprise mutually co-operating positioning elements with which the gripper head is precisely positionable with respect to the work station. Due to the process of precisely positioning the gripper head relative to the work station on each occasion, this solution offers the chance of positioning the module relative to the gripper head on the one hand, and thereafter of simultaneously precisely positioning the module relative to the work station on the other.
In order to enable the module carrier to be moved relative to the individual work stations, provision is preferably made for the module carrier to comprise a driver unit with which it is movable relative to the base unit. A driver unit of this type may be constructed in the most varied of manners.
For example, it would be conceivable to provide a geared drive for this purpose. However, it is also advantageous to provide an electromagnetic, electrostatic or pneumatic, directly driven linear motor for the purposes of moving the module carrier.
Furthermore, provision is preferably made for the module carrier to comprise a coupling unit with which energy is adapted to be coupled into the module carrier, for example, in an inductive manner.
Hereby, the coupling unit is preferably associated with a respective work station so that when positioning the module carrier near the respective work station, the coupling unit will automatically cater for coupling in the energy required for the functioning of the module carrier.
Moreover, the coupling unit is preferably also utilisable for effecting a coarse positioning of the module carrier on the base unit relative to the currently relevant work station.
In order to be able to effect exact positioning of the gripper head relative to the currently relevant work station, provision is preferably made for the module carrier to comprise positioning units with which the gripper head is movable relative to a base element of the module carrier. The precise positioning of the module relative to the respective work station can then be effected with the aid of this positioning unit.
One particularly advantageous concept of a module carrier in accordance with the invention, envisages that the module carrier should comprise a base element and an extension arm which supports the gripper head, whereby the positioning units are preferably effective between the base element and the extension arm so that the gripper head itself will also be precisely positioned via the extension arm.
In order to be able to control the differing functions of the module carrier in a simple manner, provision is made for the module carrier to comprise a control system with which the gripper head is precisely positionable relative to the base element.
Furthermore, especially for the purposes of controlling a plurality of module carriers in common, provision is made for the control system for the module carrier to communicate with an overall control system for the device in accordance with the invention, whereby said latter system is capable of coordinating the relative movements of the plurality of module carriers.
Hereby, provision is preferably made for the control system to communicate with the overall control system by means of a non-contact making transfer of information.
In regard to the precise construction of the work stations, again, no detailed comments in regard thereto have as yet been made. Thus, one advantageous solution envisages that one of the work stations be provided with a source of laser radiation with which the laser radiation that is required for carrying out the working step therein is producible.
For the purposes of producing miniaturised modules in high volumes and with a high throughput, provision is hereby made for each of the work stations that is working with laser radiation to be provided with its own source of laser radiation.
However when producing miniaturised modules as prototypes, working models or in small to middling volumes, provision is preferably made for each of the work stations that is working with laser radiation to be supplied from a common source of laser radiation by means of switchable beam deflectors.
The work station for laser processing the module is preferably constructed such that that the laser radiation emerges from an outlet opening which faces a module positioned in this work station so that it is possible to process the module directly with the laser radiation or to deposit material on this module, whereby the material that is to be deposited is positionable between the outlet opening for the laser radiation and the module.
It is preferable if the material that is to be deposited is initially applied to a transparent support in the form of a prestructured thin film so that it becomes possible to produce a geometrically true transfer of the prestructured film.
It is preferable hereby if the source of laser radiation is constructed such that it produces pulsed laser radiation and it is especially expedient if the source of laser radiation produces laser radiation having pulse durations in the pico-second range or femto-second range.
In order to achieve particularly homogeneous processing or to be able to produce a homogeneous application of an element that is to be positioned on the module, provision is preferably made for the source of laser radiation to produce pulses having a spatially homogenous energy density (top-hat profile).
In order to achieve particularly uniform processing or to be able to produce precise application of an element that is to be positioned on the module, provision is preferably made for the source of laser radiation to produce pulses having a rectangular beam profile.
Further features and advantages of the solution in accordance with the invention form the subject matter of the following description and the sketched illustration of an embodiment of the solution in accordance with the invention.